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Showing papers on "Rise time published in 1988"


Journal ArticleDOI
TL;DR: In this article, a double-barrier resonant tunneling diode with a rise time of 2 ps was measured using the electro-optic sampling technique; this is the fastest switching event yet observed for an electronic device.
Abstract: Picosecond bistable operation has been experimentally observed for the first time in a double‐barrier resonant tunneling diode. A rise time of 2 ps was measured using the electro‐optic sampling technique; this is the fastest switching event yet observed for an electronic device. This time domain measurement adds necessary information to the understanding of the transport mechanisms in the resonant tunneling diode and is consistent with switching time limitations computed for the device. It also demonstrates that appropriately designed double‐barrier quantum well diodes have a response time comparable to that of the fastest all‐optical logic elements, and that they may be very useful in high‐speed logic applications.

102 citations


Journal ArticleDOI
N. Fujimoto1, Steven A. Boggs1
TL;DR: In this paper, the authors provide an indication of the waveshape and magnitude of transients which emerge from the SF/sub 6/GIS and propagate to externally connected apparatus, showing that external apparatus connected to GIS can be subjected to waveforms with rise-times in the range of 10-20 ns and voltage rate-of-rise as high as 40 MV/ mu s.
Abstract: The authors provide an indication of the waveshape and magnitude of transients which emerge from the SF/sub 6/ GIS and propagate to externally connected apparatus. Capacitively graded bushings, overhead line connections, etc. tend to reduce the magnitude and cause a slight degradation in the rise-time. Computer simulations and measurements have shown that external apparatus connected to GIS can be subjected to waveforms with rise-times in the range of 10-20 ns and voltage rate-of-rise as high as 40 MV/ mu s. This is comparable to or in excess of the rate of rise during a chopped wave test. >

51 citations


Patent
Kobayashi Toshifumi1
13 Jan 1988
TL;DR: In this paper, a power on reset pulse generating circuit was proposed, which comprises a flip-flop coupled through capacitors to an applied supply voltage to be resettable thereby, a time constant circuit including an array of diode connecting MOS transistors and a capacitor coupled to reset the flipflop in response to a fast rise time of an applied input voltage.
Abstract: A power on reset pulse generating circuit, which comprises a flip-flop coupled through capacitors to an applied supply voltage to be resettable thereby, a time constant circuit including an array of diode connecting MOS transistors and a capacitor coupled to reset the flip-flop in response to a fast rise time of an applied supply voltage, and another MOS transistor connected to detect a level of a voltage at the output terminal to reset the flip-flop in response to a slow rise time of the applied supply voltage.

35 citations


Patent
24 Mar 1988
TL;DR: In this paper, a series-connected MOSFET switch with series-connections is presented, in which the MOS-FETs are controlled largely independently of their number both with especially low impedance and with high DC isolation.
Abstract: Switch with series-connected MOSFETs, in which the MOSFETs are controlled largely independently of their number both with especially low impedance and with high DC isolation. For this purpose, the MOSFETs (T1, T2, T3...Tn) are in each case associated with their own ferrite ring core pulse transformers (UA), the primary circuits (WP) of which are formed by a single line (LA) which is continuously insulated for high voltage and which is conducted once through all ring cores (K) of the pulse transformers (UA). When a voltage pulse is applied to the input terminal (EA), the driver MOSFET (TA) is turned on and voltage pulses are transmitted at the same time through all pulse transformers (UA) to the control terminals (G) of the MOSFETs (T1, T2, T3...Tn), which causes them to be turned on synchronously. The turn-on rise time of the switch is of the order of 1 nanosecond per 1 kilovolt rated voltage with a resistive load. The invention can be used, for example, in the electro-optical Q-switching of lasers.

32 citations


Journal ArticleDOI
TL;DR: An analyser's rise time can be estimated clinically to within 10 (SD 8) ms by a simple breath hold and forced exhalation, thus providing an estimate of the accuracy of carbon dioxide measurements in adults or children.
Abstract: Carbon dioxide measurements are not accurate, especially in children, if the response time of the carbon dioxide analyser is too slow and its output fails to reach the actual carbon dioxide concentration at the end of the breath. The distortion of the carbon dioxide waveform is a function of the "rise time" of the analyser. We have simulated an expired carbon dioxide curve and calculated the rise time required to measure accurately end-tidal carbon dioxide and VCO2 in adults and children. A rise time of 80 ms (10-70%) is sufficient to measure end-tidal carbon dioxide concentration with 5% accuracy in patients with rates of ventilation less than 100 b.p.m. and I:E ratios less than 2:1. We have measured the rise time of 11 commercially available carbon dioxide analysers and found that only six of the 11 responded quickly enough to be accurate for rates up to 100 b.p.m. All 11 responded rapidly enough to measure end-tidal carbon dioxide concentration with 5% accuracy when ventilatory rates were less than 30 b.p.m. To measure VCO2 with 5% accuracy, an analyser should have a rise time of 20 ms. Only one analyser met this specification. An analyser's rise time can be estimated clinically to within 10 (SD 8) ms by a simple breath hold and forced exhalation, thus providing an estimate of the accuracy of carbon dioxide measurements in adults or children.

32 citations


Patent
15 Sep 1988
TL;DR: In this paper, a Marx high voltage generator with a fast rise time is presented, where photoconductive semiconductor switches are sequentially triggered by a single laser via fiber optic bundles of different lengths.
Abstract: A Marx high voltage generator with a fast rise time. Photoconductive semiconductor switches are sequentially triggered by a single laser via fiber optic bundles of different lengths. The switches serve to series connect a group of charged capacitors. Output is taken from the last capacitor which receives the voltage accumulated on all of the previous capacitors. Proper timing of the activation of each switch produces a fast rise time.

26 citations


Proceedings ArticleDOI
24 Oct 1988
TL;DR: In this paper, the authors measured transmittance vs voltage and response time characteristics of polymer-dispersed liquid crystal (PDLC) films for temperatures from -10°C to 60°C.
Abstract: Polymer-dispersed liquid crystal (PDLC) films, consisting of micrometer-sized liquid crystal (LC) droplets dispersed in a polymer matrix, have considerable promise for a variety of electro-optic applications. VVe report the first measurements of the electro-optic performance of PDLC films over an extended temperature range. These properties are strongly sensitive to the liquid crystal microdroplet size. Calorimetric studies have shown that the droplet size is controlled by the rate at which the film is cured while the operating temperature range is determined, not by cure rate, but by the choice of liquid crystal and polymer matrix material. We have measured transmittance vs voltage and response time characteristics of PDLC films for temperatures from -10°C to 60°C. For thin (≈ 17.5 μm) films, transmittance of 70% or greater is achieved over this entire temperature range for driving voltages below 60 Vrms. Off-state transmittance of collimated light) is typically about 17o. The threshold voltage, at which transmittance begins to increase from its off-state value, and the voltage needed to achieve maximum transmittance both decrease with increasing temperature. Response times are rapid compared to those of conventional nematic liquid crystal devices. At a 60 Vrms driving voltage, rise time decreases from about 250 μs to 500 μs as temperature increases from -10°C to 60°C; even shorter rise times are measured at higher driving voltages. Decay times are nearly independent of voltage at temperatures above 0°C; at subzero temperatures, decay time increases with increasing voltage. This behavior can be explained in terms of molecular reorientation within the PDLC film. Decay times at -10°C range from 300 ms to 600 ms for voltages between 60 and 120 Vrms ; at temperatures above 15°C, decay times are below 50 ms for all voltages in this range. These results suggest that PDLC films of 12-25µm thickness are promising systems for future automotive displays.

24 citations


Journal ArticleDOI
TL;DR: A new system is presented here, whose design is based on the electrochemical phenomena occurring on the platinum electrode, and which improves the response of the electrode to a rise time of 4 ms and a decay time constant of 21 ms, without the signal being distorted by filters and without using the first derivative of the signal.
Abstract: A new system is presented here, whose design is based on the electrochemical phenomena occurring on the platinum electrode that we examined before [P. Meunier and R. Popovic (unpublished)]. The architecture of the system is articulated around an IBM‐PC computer which controls the polarization of the electrodes, the triggering of the flash lamp, and the acquisition of data. The potentiostat circuit and new electrode design improve the response of the electrode to a rise time of 4 ms and a decay time constant of 21 ms, without the signal being distorted by filters and without using the first derivative of the signal. This polarograph shows a 50‐dB signal‐to‐noise ratio (0.3% error) during experiments with the motile algae Dunaliella tertiolecta. The determination of amplitudes of oxygen production is performed with third‐order cubic spline interpolations, after subtraction of the current base line. The resulting accuracy and reproducibility will enable researchers to attain a higher degree of refinement in ...

22 citations


Journal ArticleDOI
TL;DR: In this paper, the operation principles of the two-dimensional position-sensitive silicon detector were studied using a simple model, which treats the detector as an area of continuously distributed capacitance C and resistance Rs of position surface layer.
Abstract: The operation principles of the two-dimensional position-sensitive silicon detector newly developed by Doke et al. were studied using a simple model. This model treats the detector as an area of continuously distributed capacitance C and resistance Rs of position surface layer. A linear relationship can then be obtained between the position of the incident particle and change collected at the contacts of the detector. The kinetics of charge collected at corner contacts, ballistic deficit and noise were calculated. Rise time of the charge pulse (10–90%) was found to vary with the position of incidence up to about RsC/8. It was found that a shaping time constant longer than RsC/3 is required for pulse shaping with single CR-differentiation and single CR-integration in order to obtain a ballistic deficit of less than 1%.

21 citations


Journal ArticleDOI
20 Apr 1988
TL;DR: In this article, the authors proposed a technique for measuring instantaneous power and energy losses in static switching devices during different operating intervals (turn-on delay, rise time, on-state, turn-off delay, full time, and off-state) of a switching cycle.
Abstract: A novel technique is proposed for measuring instantaneous power and energy losses in static switching devices during the different operating intervals (turn-on delay, rise time, on-state, turn-off delay, full time, and off-state) of a switching cycle. To this end, a system for measuring voltages and currents is used, based on sampling at 200 Ms/s for data acquisition. The data are then transferred to a personal computer (PC), where they are conditioned and processed to obtain the instantaneous values and the average values of power losses for any desired duty cycle or single impulse. It is concluded that the high-speed digital acquisitions of voltage and current data along with the possibility of automatically processing on a PC allows the calculation of the losses during the fast switching transients with a greater degree of accuracy and detail than that afforded by classical techniques. >

20 citations


Patent
22 Dec 1988
TL;DR: In this article, the authors proposed an operational amplifier, which compares the voltage across the transmitting module with a gated programmable digital voltage reference, and a high bandwidth power transistor serially connected with the load, the conductivity of which is controlled to adjust the load voltage to the reference value.
Abstract: The invention relates to compact means for turning power on and off and regulating that power as it is supplied to a pulsed transmitting module in a phased array radar system. The arrangement comprises an operational amplifier, which compares the voltage across the module with a gated programmable digital voltage reference, and a high bandwidth power transistor serially connected with the load, the conductivity of which is controlled to adjust the load voltage to the reference value. Capacitive coupling prevents burnout of the transmitting module from a sustained "on" signal and a capacitive feedback connection at the operational amplifier limits the rise time of the voltage supplied to the load to avoid ringing. The use of a "switch" in a regulating mode reduces the amount of local storage capacity required to achieve comparable regulation, and leads to a power conditioner for an individual transmitting module, which is both compact and of high performance. The programmable nature of the voltage reference allows for convenient "tapering" of the power supplied from each module to the associated antenna element.

Journal ArticleDOI
TL;DR: In this article, different startup modes of a reversed-field pinch (RFP) are examined and compared and an analytic expression is given for characterizing the V⋅s contributions of the toroidal loop voltage during the current rise in ramped discharges is found.
Abstract: The different startup modes of a reversed-field pinch (RFP) are examined and compared The RFP startup is not the same as startup of other toroidal devices such as the tokamak because of the spatial and temporal variations of the toroidal field and the reversed toroidal field in the outer region of the pinch near the wall In matched mode startup, used in many RFP experiments today, the toroidal flux is held constant during the current rise, with the field reversal occurring before the peak current This mode, with its short rise time, has a low volt-second (V⋅s) input but requires a high toroidal voltage to reach a specific current in a relatively short time In a ramped current mode, alow current RFP discharge is ramped to its final peak value The toroidal flux needed as the current rises is generated by a dynamo action This slower startup mode can be driven by a lower voltage but requires more V⋅s input than the matched mode Different startup modes in the ZT-40M experiment at Los Alamos are compared and an analytic expression is given for characterizing the V⋅s contributions The resistive component of the toroidal loop voltage during the current rise in ramped discharges is found to depend on theta (Θ = Bpol(wall)/Bave)- At a theta of 145, the resistive voltage has a minimum and it has been possible to reduce the V⋅s input by as much as 40% in ramp discharges by keeping theta close to this value

Proceedings Article
25 Apr 1988
TL;DR: In this article, the authors report the generation of electrical wavefronts with 7.8-ps fall time by propagation on a GaAs monolithic nonlinear transmission line with step-recovery and funnel diodes.
Abstract: Picosecond pulse generators are central components for high-speed electronic instrumentation. Step-recovery diodes generate ~10-V transitions of 35-ps rise time, while funnel diodes generate ~0.2-V 25-ps transitions. We report generation of electrical wavefronts with 7.8-ps fall time by propagation1,2 on a GaAs monolithic nonlinear transmission line.

Journal ArticleDOI
TL;DR: In this article, the authors used realistic source time functions in an anelastic material characterized by frequency-independent internal friction to demonstrate that the source time function strongly influences the dependencies of initial rise time τ and pulse width w on internal friction Q-1 and distance x.
Abstract: Numerical examples of one‐dimensional (1-D) wave propagation, using realistic source time functions in an anelastic material characterized by frequency‐independent internal friction, demonstrate that (a) the source time function strongly influences the dependencies of initial rise time τ and pulse width w on internal friction Q-1 and distance x; (b) in general, τ and w have different functional dependencies on Q-1 and x; and (c) the slope ∂τ/∂x for particle displacement computed for a band‐limited source time function can be either greater than or less than the corresponding value computed for a delta‐function displacement source time function. Result (a) corroborates the result for τ given by Blair and Spathis, which implies that the commonly used linear rise time and distance relation, τ=τ0+CT/Q, where T is the traveltime and C a source‐independent constant, is an oversimplification of 1-D anelastic wave propagation; the source spectrum must be considered when inferring seismic attenuation from changes ...

Journal ArticleDOI
01 Jul 1988-EPL
TL;DR: In this article, a superconducting Nb film was observed to have a rise time of less than 150 ps (resolution limit of the electronic detection system) and decay time varying from 2 to 1.3 ns.
Abstract: Transient response of a 2500 A thick superconducting Nb film to the impact of a single 129Xe50+ ion of total energy 3.2 GeV, transferring about 2.4 keV/A of electronic excitation energy, was observed by means of a superconductor-insulator-superconductor tunnel junction attached to the film some distance away from the impact point. The response had rise time of less than 150 ps (resolution limit of the electronic detection system) and decay time varying from 2 to 1.3 ns as function of temperature. Main experimental features, if not finer details, are in good agreement with Rothwarf and Taylor theory of nonequilibrium processes in superconductors.

Proceedings ArticleDOI
05 Jun 1988
TL;DR: In this article, a uniform field electrode system is used to measure the partial discharge in polyethene sheets at 50-Hz AC voltages, with rise times of about 1 to 1.5 ns.
Abstract: The mechanism of partial discharges inside a void is investigated using a uniform-field electrode system. To allow fast measurements of the partial discharge current, one of the electrodes is split into a central measuring disk and surrounding ring which acts as a coupling capacitor. The minimum permissible diameter of the disk depends on the gap width (Ramo-Schockley effect). A 400-MHz Tektronix oscilloscope 7844 or a digitizer (7912AD) is used, allowing measurements with rise times down to about 1 ns. Fast current measurements in polyethene sheets at 50-Hz AC voltages are reported. The rise time (10-90%) is about 1 to 1.5 ns. The measured charge does not differ greatly from theoretical calculations of the apparent charge (67-76 pC range as opposed to a calculated value of about 66 pC). This indicates that the entire void area discharge and not just part of it. >

Journal ArticleDOI
TL;DR: In this article, the response characteristics of a two-stage CuSO4 solution "tube" in a concentric cylindrical configuration for measuring high-voltage nanosecond pulses have been studied.
Abstract: The response characteristics of a two‐stage CuSO4 solution ‘‘tube’’ resistive divider placed in another CuSO4 solution ‘‘tube’’ in a concentric cylindrical configuration for measuring high‐voltage nanosecond pulses have been studied. The test results showed that it was capable of maintaining pulse rise time less than 10 ns, and the hold‐off voltage for pulses with rise times less than 10 ns was 600 kV.

Journal ArticleDOI
TL;DR: In this article, a method is proposed for determining the correct settling level of the step response to reduce the great uncertainty in the evaluation of the rise time, which proved to be effective for three different types of impulse dividers.
Abstract: The expression of the transfer characteristic of a HV impulse divider by a limited number of response parameters is considered. The response parameters under consideration for introduction into the revised standard for HV impulse tests are summarized, and the errors in the evaluation of the response time, and time standard rise time, are discussed. A method is proposed for determining the correct settling level of the step response to reduce the great uncertainty in the evaluation of the rise time. The method proved to be effective for three different types of impulse dividers. >

Journal ArticleDOI
TL;DR: In this article, the authors describe the theory, design and performance of a linear coil used to measure distributed current pulses, where the linear-wound coil acts as a delay line, and its response to transient signals is studied for a generic excitation and for various terminating impedances.
Abstract: Describes the theory, design and performance of a linear coil used to measure distributed current pulses. The linear-wound coil acts as a delay line. Its response to transient signals is studied for a generic excitation and for various terminating impedances. The probe rise time is less than 1 ns, the attenuation is about 5.3 mV A-1 and it can record currents up to tens of kA.

Patent
24 Jun 1988
TL;DR: In this article, an improved circuit for driving a discharge load such as a spark plug, a discharge elec-trode of a combustor or the like is provided, which is formed into a forward type circuit configuration which feeds to the discharge load a high voltage output generated in high voltage coil of a transformer in accordance with turn-on of a switching element actuated to switch on and off a d-c input supplied through a low voltage coil.
Abstract: There is provided an improved circuit for driving a discharge load such as a spark plug, a discharge elec­trode of a combustor or the like. It is formed into a forward type circuit configuration which feeds to the discharge load a high voltage output generated in a high voltage coil of a transformer in accordance with turn-on of a switching element actuated to switch on and off a d-c input supplied thereto through a low voltage coil of the transformer. Consequently, exact ignition can be effected in the discharge load without failure under the condition that the rise time is shortened and still the duration of high voltage application is set to be suffi­ciently long equivalently.

Journal ArticleDOI
TL;DR: In this paper, the breakdown voltage reached a maximum value as the rise time increased, and reduced at longer rise times, and an extremely high breakdown voltage was obtained with the addition of a very small percentage of SF6 to N2.
Abstract: The corona and breakdown characteristics of gas mixtures were investigated in a positive needle gap, using µs pulse voltage with various rise times. The breakdown voltage reached a maximum value as the rise time increased, and reduced at longer rise times. An extremely high breakdown voltage was obtained with the addition of a very small percentage of SF6 to N2.

Journal ArticleDOI
TL;DR: In this article, an ion-implantation technique used to create high-speed photoconductive devices in semi-insulating gallium arsenide (GaAs) is described.
Abstract: An ion-implantation technique used to create high-speed photoconductive devices in semi-insulating gallium arsenide (GaAs) is described. The effects of electrical contacts, GaAs substrate material, and various implant parameters on device performance are presented. The best measured performance characteristics of sampled (correlation) waveforms are: full-width-at-half-maximum of 4.5 ps, rise time (10 to 90% of full amplitude) of 3.2 ps, and signal-to-noise ratio of approximately 50 dB (integration time is 10 ms). >

Patent
05 Feb 1988
TL;DR: In this article, an FM multipath noise reduction circuit is described, in which a condenser for rapid charging is connected between the power source line and a charge/discharge condenser disposed in a level shift circuit system so that the rise time constant of the control output voltage at the power-source switch-on, the AM/FM mode switch over, etc.
Abstract: An FM multipath noise reduction circuit is disclosed, in which a condenser for rapid charging is connected between the power source line and a charge/discharge condenser disposed in a level shift circuit system so that the rise time constant of the control output voltage at the power source switch-on, the AM/FM mode switch over, etc. is equal to that after the power source switch-on.

Journal ArticleDOI
TL;DR: In this article, the effect of impedance mismatch on shock-pressure enhancement in laser-irradiated layered targets has been investigated by numerical simulation of the entire time history of shock generation, and it is found that it is possible to enhance the attainable values of compression (ρ/ρ0) and shock pressure with a given laser pulse by suitable optimization of the target.
Abstract: The effect of impedance mismatch on shock‐pressure enhancement in laser‐irradiated layered targets has been investigated by numerical simulation of the entire time history of shock generation. The model is a simple, one‐dimensional, single‐temperature Lagrangian hydrodynamic code incorporating a simplified laser‐absorption model and an equation of state suitable to describe the thermodynamic state of matter in a wide range of density and temperature. Effects of change in layer materials and other experimental parameters on the attainable shock pressure and compression have been studied. From an exhaustive study of such targets, it is found that it is possible to enhance the attainable values of compression (ρ/ρ0) and shock pressure with a given laser pulse by suitable optimization of the target. A pressure of more than 60 Mbar can be generated with a 1014 W/cm2, 300‐ps rise‐time laser pulse in such targets. In order to generalize the applicability of the results, within existing experimental uncertainties of measurements, and facilitate a suitable target design for any laser system, simple scaling laws are obtained in terms of parameters like intensity and rise time of the laser pulse.

Journal ArticleDOI
TL;DR: In this paper, a dual-sided proton-irradiation technique and a technique that combines anode shorting and proton irradiation were proposed to obtain low-loss high-power static induction thyristors (SIThys).
Abstract: Two techniques are proposed to obtain low-loss high-power static induction thyristors (SIThys). A dual-sided proton-irradiation technique and a technique that combines anode shorting and proton irradiation both provide n-channel and p-channel SIThys with high blocking voltages and a good trade-off between switching times and forward voltage drops. In particular, dual-sided proton irradiation provides a SIThy with forward and reverse blocking voltage higher than 1 kV. An n-channel SIThy with an n-region thickness of 230 mu m has shown a rise time of 0.24 mu s, a storage time of 0.19 mu s, a fall time of 0.08 mu s, and a forward voltage drop of 3.0 V at an anode current of 50 A (125 A/cm/sup 2/). The effect of the combined technique is much the same as that of the dual-sided proton irradiation. Using the dual-sided proton irradiation, a p-channel SIThy with a p-region thickness of 430 mu m has shown a rise time of 0.5 mu s, a storage time of 0.1 mu s, a fall time of 0.3 mu s, and a forward voltage drop of 6.0 V at an anode current of 4 A (110 A/cm/sup 2/). Using the proposed techniques, a complementary high-power control circuit with low loss and switching frequency higher than a few hundred kilohertz can be realized. >

Patent
24 Feb 1988
TL;DR: In this paper, the authors proposed a method to prevent the increase of the transient output power of an oscillation circuit, and to set a luminous output at a set value automatically by providing a means in which the rise time when high-frequency currents are superposed to laser driving currents is made simultaneous with or later than the response time of an automatic output control loop.
Abstract: PURPOSE: To prevent the increase of the transient output power of an oscillation circuit, and to set a luminous output at a set value automatically by providing a means in which the rise time when high-frequcncy currents are superposed to laser driving currents is made simultaneous with or later than the response time of an automatic output control loop. CONSTITUTION:An optical disk 2 for an optical disk device 1 is turned and driven by a spindle motor arranged in the vertical direction, an optical head 3 is disposed oppositely to one surface of the disk 2, and the disk 2 is irradiated with light beams. A laser diode 5 is housed in the head 3, and the diode 5 is controlled by output currents from an APC circuit 7 for controlling power. The diode 5 is supplied with high-frequency currents from an oscillation circuit 8 for high-frequency superposition. A pin photodiode for monitor is sealed into the diode 5, and luminous a output in case of the operation of the circuit 8 is set automatically to set-value power by the currents of the diode.

Patent
02 Mar 1988
TL;DR: In this paper, the authors proposed a method to prevent problems of biting and passing-through of a rolled stock to suppress the flaws on a inner surface and to improve the rolling efficiency by measuring the biting time and the passing through of the rolled stock time to obtain both slip ratios based on the measured values, comparing with a reference slip ratio and controlling a set value of rolling for the next material to make the difference to be zero.
Abstract: PURPOSE:To prevent problems of biting and passing-through of a rolled stock to suppress the flaws on a inner surface and to improve the rolling efficiency by measuring the biting time and the passing-through of the rolled stock time to obtain both slip ratios based on the measured values, comparing with a reference slip ratio and controlling a set value of rolling for the next material to make the difference to be zero. CONSTITUTION:As to signals of a load cell 43, the time from a rise time to a reach time reaching a load value of a load level setting derive 51 for the rolling is denoted as the biting time t1 and stored in an arithmetic and storage device 54. More, from the reaching time of the output of the load cell to the load value of the rolling load level setting device 51 to the time of departing the rolling material from the rolls is denoted as the passing-through time t2 to store in the same device 54. Then, the biting time t1 and the passing-through time t2 are given to an arithmetic and control device 55 to calculate the slip rate at biting and passing-through time. After that, comparing with the slip rate capable of boring by a reference setting device 58, the next roll setting value is controlled when both slip rates are under the reference value, the difference between the slip rate and the reference slip rate is to become zero, and when the both sides or one side of the slip rates are over the reference value, the difference between the higher slip rate and reference value is to become zero.

Journal ArticleDOI
TL;DR: In this article, an impulse generator delivering 15 V to a 50 Omega load with a rise time of 70 ps and FWHM 175 ps was presented, which is suitable for antenna reflection and transmission measurements from 0.1 to 10 GHz without the need for an anechoic chamber.
Abstract: Practical details are given of an impulse generator delivering 15 V to a 50 Omega load with a rise time of 70 ps and FWHM 175 ps. Special attention to the settling time (500 ps to 40 dB down) makes the generator suitable for antenna reflection and transmission measurements from 0.1 to 10 GHz, without the need for an anechoic chamber.

Proceedings ArticleDOI
11 Apr 1988
TL;DR: In this article, a VDMOS (vertical double-diffused metal-oxide semiconductor) transistor structure is proposed that reduces reverse transfer capacitance by an additional p-region formed at the surface of the n-epitaxial layer.
Abstract: A VDMOS (vertical double-diffused metal-oxide semiconductor) transistor structure is proposed that reduces reverse transfer capacitance. The structure features an additional p-region formed at the surface of the n-epitaxial layer, using a poly-Si gate as a mask. Its measured reverse transfer capacitance is about 50% less than that of the conventional VDMOS, and the rise time reduced 50%. measured I/sub D/-V/sub DS/, drain-source breakdown, and switching characteristics are also presented. >

Patent
28 Mar 1988
TL;DR: In this article, a high power microwave expander is provided which decreases the rise time of rf pulses, where internal conductors are separated and tapered to provide a high isolation characteristics at low power.
Abstract: An high power microwave expander is provided which decreases the rise time of rf pulses. The expander is a transmission line in which internal conductors are separated and tapered to provide a spark gap with high isolation characteristics at low power. The arcing threshold of the spark gap can be adjusted by varying the internal pressure of the transmission line, injecting a gas such as helium into the transmission line and by providing free electrons in close proximity to the spark gap.